In the news today...the latest Facebook firestorm. As part of a collaboration with researchers, Facebook apparently altered users’ News Feeds to measure the effect those changes would have on the emotional tenor of users’ posts.

As it turns out, according to the paper, which was just published in the Proceedings of the National Academy of Sciences, the effect was small but statistically significant. So the results are informative about the impact of emotional contagion.

But what is drawing the headlines are the ethical ramifications of the study design. Is it cool for Facebook to manipulate people’s News Feeds in this way? Even the Princeton psychology professor who edited the study admits, “I’m still thinking about it and I’m a little creeped out, too.”